ALLUVIAL DIVISION. 45 
has any doubts of the certainty of its indications in demonstrating the habits and general cha¬ 
racters of animals, when subjected to the investigations of an able comparative anatomist. 
To the Baron Cuvier, we are indebted for a large share of the knowledge of comparative 
anatomy that we possess, and almost exclusively for an application of the principles of that 
science to fossil bones. The laws that regulate the forms of the various parts of animals are 
well illustrated by Cuvier. He remarks : 
“ Every organized being consists of parts which correspond mutually, which concur by 
means of reciprocal influences in the production of a common end, and thus form together a 
whole, a perfect system. No one part can change without the others being modified ; and 
consequently each, taken separately, modifies all others.” 
If the intestinal structure of an animal be fitted only for digesting flesh recently killed, its 
jaws must be fitted to devour, its claws to seize and tear, its teeth to cut and divide, and 
its entire system of organs and limbs for pursuing and catching its prey, and the perceptive 
faculties must be fitted to discern that prey afar off. It is necessary also that he should have 
seated in his brain the instinct to hide himself, and spread snares for his victim. Such are 
the conditions necessary for every carnivorous animal; without them the species could not 
subsist.* * 
“Besides these general conditions, there are subordinate ones, relating to the size, the 
species, and the abode of the prey; and each of these secondary conditions give rise to dif¬ 
ferences of detail, in the forms which result from the general laws. Hence not only the 
class, but the order, the genus, and even the species are expressed in the form of each part.” 
A jaw of a certain force must have a suitable articulation, and a sufficiently large tem¬ 
poral muscle, indicated by the hollow formed in the bone for its reception, and by the convexity 
of the strong zygomatic arch. An animal which carries off his prey, must have strong 
muscles to elevate the head; and the parts of the vertebras and of the occiput to which they 
are attached, must have a form to correspond with this intention.! 
“ For dividing flesh, cutting teeth are required ; and they must be more or less cutting, 
in proportion as they are more or less exclusively occupied in that way. Their basis must 
be solid if they are employed in breaking and comminuting bones, particularly if the bones 
are strong. These circumstances will influence the development of all the parts employed 
in moving the jaw.” 
“ Mobility of the toes, and strength of the nails, are necessary for seizing the prey; 
hence arise determinate forms of the phalanges, and particular distribution of the muscles and 
tendons. There must be a power of rotating the forearm, and consequently a particular 
■who were younger, selected for this purpose continually, and repeatedly instructed in these things which were thus handed down 
from generation to generation; and that there was a tradition among the Indians of the existence of these animals ; that they were 
often seen; that they fed on the boughs of a species of lin tree ; that they did not lie down, but leaned against a tree to sleep. 
* Bakewell’s Geology, 2d Am. Ed. p. 230. 
t Museum of Foreign Literature, Vol. 26, p. 215. 
